Grease gun



May 31, 1932. D. J. LOCKWQOD 1,860,116

GREASE GUN Filed NOV. 21, 1950 Patented May 31, 1932 UNT STATES "PATENT orifice DOUGLAS J. Locxwoon, on oNAwA, lIOWA f ernaast:v GUN l Application led November 21, 1930. Serial No. 497,214.

with means for dispensing the lubricant in small quantities under pressure and applying it to parts of a motor vehicle or other machines such as are usually equipped with lubricant supply connections.

A further obj ect of the invention is to provide improved and highly eiiicient discharge means or means for dispensing the lubricant under pressure and so arranged as to eliminate loss of pressure or back pressure toward the grease container.

Still another object of the invention is to provide a grease gun which is simple of construction, highly efficient and which is rela-v tively inexpensive to manufacture because it i contains few moving parts and few parts which require machine work or other expensive operations and in which the operating parts are arranged so that they are easily accessible for assembly and repair'.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure 1 is a perspective View plete device.

ofthe com- Figure 2 is an enlarged longitudinal section of the dispensing apparatus or gun proper, the piston rod being shown in extended or depressed condition. Y

Figure 3 is a similar view of one of the same parts with the piston rod in partly retracted or elevated position. y

Figure 4 is a vertical section on the line 4--4 of Figure 2, illustrating particularly the valve controlled communication between the container and the dispensing apparatus.

In the drawings I have employed the nu-` meral 10 to designate the grease container. This member preferably is cylindrical and is formed at its upper end with an integral wall 12 and is also formed with a carrying handle 14 rising-therefrom. At its lower end the container body 10 is formed with an out- Wardly projecting peripheral flange 16 and the lower end of the container is closed b-y a. separate plate 18 `attached to the flange 16 by means of a plurality ofbolts 20. The bottom plate 18 preferably is shouldered so as to have a thickened portion fitting snugly within the wall of the container 10 as shown particularly in Figure 4, and an annular gasket 22 s ismounted between the flange 16 and the marginal portion of said plate whereby a tight joint is procured.

A discharge port 24 is formed through the wall of the container 10 and through aboss 26 'which projects outwardly from thelower part of said wall just above the flange 16. As shown in Figure 4 the discharge port 24 hasa part which extends downwardly to the horizontal level of the upper surface of the bottom plate 18 so thatsubstantially all of the contents of the container may readily vbe discharge through said port.` The dispensing apparatusincludes an elongated cylinder 28 of relatively small diameter as compared with the diameter of the container` 10 and also of considerably less length. The cylinder 28 is mounted in upright position of the outside of the container 10 with its lower end adjacent the boss 26 and is attached to the container by means of cap screws 30 extendingthrough apertured ears 82 onthe cylinder and seated in bosses 34 on the container wall. Y v A piston rod 36 is tted snugly within the cylinder 28 and arranged for reciprocation.

The pistonrod projects from the upper end ofthe cylinder through a packing gland 38 and is provided with aclevis 40 on its upper end.

An operating lever 42 is fulcrumed on the top wall 121 of the container by means of a pin 44 carried by a pair of spaced apertured ears 46on said top wall. The operatinglever 42 is pivotally connectedto the clevis 40 of the piston rod by means of a link 48 which, as here` shown, is arranged for reciprocationV between spaced lugs 50 the container 10. l f

As here shown, thev operating lever 42 is off formed on the wall of ino relatively short and does not project a material distance beyond the margin of the container 10. However, it is formed with a longitudinally arranged bearing boss 52 adapted to receive a removable handle member 54 which provides the desired amount of leverage for manual operation of the dispensing apparatus. When the device is not in use the removable handle 54 may be carried by a pair or apertured ears 56 projecting laterally from the container wall.v Y

Near the lower end of the cylinder 28 the dispensing apparatus is formed with a transversely arranged projection 58 having a cross bore 60 communicating with thelower end of the bore of the cylinder 2.8. The transverse projection 58 extends i'n bot-h directions from the cylinder 28 and one end of the cross bore 60 is closed by means of la screw plug 62.

Adjacent its closed end the transverse ezitension 58 is provided with a threaded nipple 64' communicating with the VAbore 60. and adapted to receive attachment of a dispensing hose 66 which preferably is of 'the armored type. The hose '66 is equipped at one end with Va coupling member 68 for attachment to the nipple 64 and 'at its opposite end with a coupling member 7 0 adapted to be applied to and communicate with a fitting, not shown, of the type commonly provided on spring shackles, parts of the steering gear and other parts of a motor vehicle to constitute lubricant 'supply connections. Y Y' The dispensing apparatus also is formed with a downward projection 72 below the transverse extension 58 Asaid downward extension is in line with the cylinder 28 and is bored to correspond therewith and to. receive the lower end ofthe 'piston rod V86 as shown in Figure 2. The lower end of `the downward e'zt'ension 7 2i's normally closed by means of Aa screw plug 74. j v

The other end of the transverseprejecti'on 58mc'omniuni'cates with aan inletchaniber l76 what as appel; en@ nor-many @10a-:d by means of a screw plug 7,8. j The inlet chamber 76 communicates at its lower end with la substantially L-fshaped inlet 'passage 80, the lower end ko" which communicates 'with 4the discharge port 24 of the container I0.

. The shoulder formed between the inlet chamber 76 Vand the reduced inlet "8() constitutes 'a yvalve seat upon which a ball valve 82 norm/ally rests. `The ball 82 consaintes 'a check valve to prevent escape 0f the contents of the inlet chamberf78 and c'oi'nmunic'atin'g passages toward the 'container and also to prevent loss of pressure inthat direction ofthe pressure effect ofthe piston rod '86. Upward movement of the ball 82 is limited by afstud 84 projecting downwardlyxrrom theoscrew c-'apz78. l j, Y ,Y

The lower part of'theinlet chamber 7 6 is provided with external ape'tu-red ears or flanged portions 86 Vadapted -to be secured to the outer face of the boss 26 by means of cap' screws 88, with a gasket 89 interposed.

The lower end portion of the piston rod 36 is formed with an end opening recess 90 and a relier port 92 extends laterally from the upper end of said recess and opens to the surface of the piston rod 36 at a point spaced a material distance above its lower end.

The bore oi the Cylinder 28 is formed with 'a relief bypass 94 which is vertically arranged and.communicates atits lower end with the cross bore 60 on the side toward the nipple 64. The relier port 92 of the piston rod communicates at times with the relief bypass 94, suc-h 'communication occurring during an intorinediate portion of the stroke o the piston rod. At other times the relief tport 92 or the pisonl rod communicates vdirectly with the cross bore 60, such communication occurring during the lower portion of the stroke..V

The container Al() is supplied with grease or other heavy lubricant'by invertingthe device and ,removing the bottom platek i8, after which the plate is replaced andthe loolts 2O drawn up tight to prevent leakageof'the contents l j A l 'l Air under pressure may be introduced-to the 'container i0 by means of a valve stem 96 extending through the top wall l2. The

valve stem 96 is of the type commonly einployed for receiving connection of anairliose or pumpI hose for inlating pneumatictires and which contains a suitable check valve dcvice, not shown', for preventingescape of the airpressure. Vhen not in use the outer end 7" or the valvestem ,96 is'closed by means tot a screw cap 98. p l rlhe air pressure in the v,container i0 is employed for the purpose of exerting pressure on the lubricant within the container and racilitating the transfer of quantities of the lubricant through the discharge port 24 to the dispensing apparatus through the suction Y action of the piston rod 36.

l/Vhen it is desired to use the grease gun for lubricatin-gparts of an automobile or other machine, the removable handle 54 is placed in the Socket 52 of the operating lever and the coupling of the dischargehose is apalife'd successiveb to the desired ittino'to i `J Y v e which `grease is to be applied f Y It will be understood that'in the use of grease dispensers of this type ja tight connection "of the coupling 70 with the fitting is v'secured 'so that the lubricant may be supplied to the fitting and thepart communicating therewith throughtlheexercise of considerable pressure toattai-n the desired penetration of the lubricant.

The operating lever 42 is oscillated mans ually on its pivot 44 by up and down movement or the outer end or the handle 54, thurs causing a reciprocation of the piston rod` through the link 48.v

, Upward movement @fthe Piston rf,

after its lower end has moved out of the bore of the downward extension 72, or in other words into the horizontal plane of the cross bore 60, exerts a suction eifect in the inlet chamber 76 through the inner end portion of the said bore. This suction raises the ball valve 82 and draws a quantity of grease from the container l0 through the discharge port 24% and inlet passage 80. cilitated and assisted by the air pressure in the container so that the inlet chamber and parts communicating therewith are entirely filled with the lubricant.

Now when downward travel of the piston rod 36 commences, the recess 90 is caused to be filled with the grease which has entered the lower part of the cylinder bore and the cross bore 60. Thus the lower end of the piston rod becomes solid and presents to the underlying grease a pressure surface commensurate with the entire area of the piston rod.

The downward pressure thus exerted causes portions of the underlying grease to travel laterally through the outer portion of the cross bore 60 and into the nipple 64 and hose 66 so that it is caused to enter the fitting to which the coupling is applied.

ln the latter part of its downward travel the lower end of the piston rod 36 passes beyond the cross bore 60 and enters the bore of the downward extension 7 2 which is closed at its lower end. At about this time the relief port 92 comes into communication with the relief bypass 94, thereby permitting lubricant from the downward extension and from the recess to pass laterally through said port and be expelled through the bypass 9i and into the outer part of the cross bore 60 and to be delivered as before.

The restricted area of the relief port 92 and relief bypass 94, taken with the fact that the piston rod is operating in a closed bore of the extension 72, has the effect of building up pressure in the latter part of the stroke of the piston rod. The additional pressure thus built up is suddenly relieved when the port 92 comes into registry with the outlet end of the bore 60, which is of greater diameter, thus resulting in delivery of the lubricant in a spurt to the tting. VThis insures that suflicient pressure will be generated to cause effective penetration of the lubricant to the more remote and close fitting parts to be lubricated.

Thus comparatively simple and very efficient means is provided for supplying the lubricant under pressure to the desired parts.

It will be understood that as soon as the downward travel of the piston rod 36 commences, the check valve 82 will be caused to seat immediately and will thus prevent escape of the contents of the inlet chamber 7 6 and of the pressure toward the container 10 and making it possible to build up pressure This action is fa-k in the opposite direction for expulsion .of the grease. i

It will be observed that all of the' parts 0f the dispensing apparatus are located eXteriorly of the grease container, thus simplifying and facilitating the operation of assembly and also the making of repairs or replacement of'parts.

' The cylindricalcontainer lOwith its closed i top, carrying handle and other appurtenances may be made integrally by a comparatively simple and inexpensive die casting process so that the entire cost of the device for parts and labor may be kept within Very reasonable limits.

I claim as my invention l. A dispensing apparatus for grease guns and the like lcomprising a cylinder, a piston i member arranged for reciprocation therein, a

cross bore intersecting the cylinder bore at a point spaced from the outer end thereof,.in let means communicating with one end of said cross bore and outlet means communicating with its other end, said piston member being formed with an end-opening rece-ss, a relief bypass formed in the cylinder wall communicating with the outlet end of said cross bore, said piston member being formed with a relief port at the inner end of said recess adapted to communicate with said bypass at times. Y

2. A dispensing apparatus for grease guns and the like comprising a cylinder, a piston member arranged for reciprocation therein, a cross bore intersecting the cylinder bore at a Vpoint spaced from the outer end thereof, an inlet chamber communicating with one end of said cross bore and outlet means communicating with its other end, check-valvecontrolled inlet means to said inlet chamber l whereby grease will be drawn into said chamber by retraction of the piston member, said piston member being formed with an endopening recess, a relief bypass formed in the cylinder wall communicating with the outlet 7' L end of said cross bore, said piston member being formed with a relief port at the inner end of said rece-ss adapted to communicate with said bypass at times.

3. A dispensing apparatus for grease guns and the like comprising a cylinder, a piston member arranged for reciprocation thereima cross bore intersecting the cylinder bore at a point spaced from the out-er end thereof, in-

let means communicating with one end of said '1" to'said outlet portion With a spurting action near the end of the piston travel.

4. A dispensing apparatus for grease guns and the like comprising acylinder, a pist-on f' member arranged for reciprocation therein, a cross bore intersecting the cylinder bore at a point spaced from the outer end thereof, inlet means communicating With one end of said cross bore and outlet means communicating With its other end, said piston member being form-ed with a recess opening toits outer end, said piston rod being formed With laterally directed communicating means opening to said recess for permitting the discharge of a relatively small amount of substance from said recess to the outlet portion of said cross bore during a portion of theoutvvard travel of the piston member and permitting the discharge of a greater amount of substance during` a subsequent portion of such travel.

Des Moines, Iowa October 29, 1930.

DOUGLAS J. LOCKYVOOD. 

